A silence black hole: Hawking radiation at the Hagedorn temperature

Understand

We compute semi-classically the Hawking emission for different types of black hole in type II string theory.

• In particular we analyze the thermal transition between NS5 branes and Little String Theory, finding compelling evidence for information recovering.
• We find that once the near horizon limit is taken the emission of a full family of models is exactly thermal even if back-reaction is taken into account.
• Consequently these theories are non-unitary and can not convey any information about the black hole internal states.